strconv: use slices.BinarySearch to simplify makeisprint.go

Change-Id: I9886a99f730b7616f6f8a5e6154e1beb7d3c79e6
GitHub-Last-Rev: 3f9dc7707377f79968e2dfcd206b83db21e60e60
GitHub-Pull-Request: golang/go#66242
Reviewed-on: https://go-review.googlesource.com/c/go/+/570535
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

1 files changed, 7 insertions, 36 deletions

diff --git a/src/strconv/makeisprint.go b/src/strconv/makeisprint.go
index ff361e7b41..767448067b 100644
--- a/src/strconv/makeisprint.go
+++ b/src/strconv/makeisprint.go
@@ -19,6 +19,7 @@ import (
 	"go/format"
 	"log"
 	"os"
+	"slices"
 	"unicode"
 )
 
@@ -31,36 +32,6 @@ var (
 	except32 []uint32
 )
 
-// bsearch16 returns the smallest i such that a[i] >= x.
-// If there is no such i, bsearch16 returns len(a).
-func bsearch16(a []uint16, x uint16) int {
-	i, j := 0, len(a)
-	for i < j {
-		h := i + (j-i)>>1
-		if a[h] < x {
-			i = h + 1
-		} else {
-			j = h
-		}
-	}
-	return i
-}
-
-// bsearch32 returns the smallest i such that a[i] >= x.
-// If there is no such i, bsearch32 returns len(a).
-func bsearch32(a []uint32, x uint32) int {
-	i, j := 0, len(a)
-	for i < j {
-		h := i + (j-i)>>1
-		if a[h] < x {
-			i = h + 1
-		} else {
-			j = h
-		}
-	}
-	return i
-}
-
 func isPrint(r rune) bool {
 	// Same algorithm, either on uint16 or uint32 value.
 	// First, find first i such that rang[i] >= x.
@@ -70,21 +41,21 @@ func isPrint(r rune) bool {
 
 	if 0 <= r && r < 1<<16 {
 		rr, rang, except := uint16(r), range16, except16
-		i := bsearch16(rang, rr)
+		i, _ := slices.BinarySearch(rang, rr)
 		if i >= len(rang) || rr < rang[i&^1] || rang[i|1] < rr {
 			return false
 		}
-		j := bsearch16(except, rr)
-		return j >= len(except) || except[j] != rr
+		_, found := slices.BinarySearch(except, rr)
+		return !found
 	}
 
 	rr, rang, except := uint32(r), range32, except32
-	i := bsearch32(rang, rr)
+	i, _ := slices.BinarySearch(rang, rr)
 	if i >= len(rang) || rr < rang[i&^1] || rang[i|1] < rr {
 		return false
 	}
-	j := bsearch32(except, rr)
-	return j >= len(except) || except[j] != rr
+	_, found := slices.BinarySearch(except, rr)
+	return !found
 }
 
 func scan(min, max rune) (rang, except []uint32) {